Isolation And Identification Of Europe Type PRRSV And Variation Analysis Of Its ORF5 Genes

Porcine reproductive and respiratory syndrome virus(PRRSV) has been one of the most important pathogens of swine science. Its emergence in the late 1980s.The disease has many clinical manifestations ,but the two most prevalent are severe reproductive failure in sows and gilts(characterized by late-term abortions, an increased number of stillborn, mummified and weak-born pigs),and respiratory problems in pigs of all ages. PRRSV belongs to the recently recognised Arterivirdae family within the genus Arterivirus, order Nidovirales. The virus is comprised of a 15 kilobase (kb) single-stranded positive sense RNA genome that is encapsulated within an enveloped, icosahedral-shaped nucleocapsid. The replicase gene covers the 5'-terminal four-fifths of the genome and is composed of two overlapping open reading frames, ORF1a and ORF1b,which are expressed from the genomic RNA. The structural genes encoded by ORF2 to 7. GP5 proteins are the most important structural protein, which is associated with immunity. According to the difference of the antigen, the isolations had been divided into the North American and European strains, the former is mostly epidemic in America and Asia, the latter is mostly epidemic in Europe, but Canadian and American researchers had isolated European strains in their country. At the present time, PRRSV had been isolated in China are all North American type. So,is there any European type PRRSV in China? There is not systemic investigation report about it at present. This research base on the technology and material of our lab, using PAMs and MARC-145 cells to isolate virus from tissue of pigs that diagnosis is the PRRSV infection, and using monoclonal antibody to identify virus in order to confirm that is there any European type PRRSV existing in China .First of all, using PAMs and MARC-145 cell, 17 virus were isolated from bloods, lymph node and lungs of pigs that diagnosis is the PRRSV infection, and using monoclonal antibody M1 that both can distinguish European type and American type PRRSV to identify virus that have been isolated, and then using monoclonal antibody M2 that can specially distinguish PRRSV Americas Nsp2 protein and monoclonal antibody M3 that specially distinguish PRRSV European Nsp2 protein to affirm the type of them. Combining fluorescence immunity...